1. Field of the Invention
The invention relates to a terminal block and to a motor provided therewith.
2. Description of the Related Art
Japanese Unexamined Patent Publication No. 2008-98007 discloses a terminal block for electrically connecting conductive members, such as busbars, extending from electric devices, such as a motor and an inverter. This terminal block electrically connects the conductive members of respective electric devices by placing the conductive members one over another on metal nuts insert molded into a terminal block body. Bolts then are screwed into the nuts to fasten the conductive members to the metal nuts.
The electric devices generally generate a large amount of heat and the heat is transferred from the electric devices to the conductive members. As a result, the terminal block connected to the conductive members becomes hot. Further, a large current flow also causes the conductive members to generate heat and makes the terminal block even hotter. Accordingly, a flat synthetic resin insulating plate is disposed below the nuts and a metal heat sink is disposed below the insulating plate. Heat from the conductive members is transferred to the heat sink via the nuts and the insulating member and is intended to be radiated to the atmosphere by a heat radiation fin on the heat sink so that the terminal block is air cooled. However, heat radiated by the heat radiation fin of the air cooled terminal block is likely to stay in a space between the heat radiation fin and a motor case to which the terminal block is fixed. Therefore, heat radiation tends to be low.
Consideration has been given to forming the heat sink with a flat bottom surface. The flat bottom surface of the heat sink could be attached to a heat radiation sheet, which in turn could be fixed to a cooled motor case. Heat of the heat sink would be transferred to the cooled motor case via the heat radiation sheet to improve heat radiation. However, the heat radiation sheet is an additional component and the need to attach the heat radiation sheet to the terminal block deteriorates mass productivity. Further, the terminal block cannot be cooled to a temperature lower than the surface temperature of the motor case, and a heat radiation effect is insufficient if the heat generation is large. Thus, further improvement has been desired.
The invention was completed in view of the above situation and an object thereof is to improve heat radiation of a heat sink without increasing the number of parts.